Estimated legacy effects from simulated post-trial data were less biased than from combined trial/post-trial data.

Abstract

“Legacy effects” describe the phenomena where treatment effects are apparent during the post-trial period that are not attributable to the direct effects observed within the trial. We investigate different approaches to analysis of trial and extended follow-up data for the evaluation of legacy effects.

We conducted a simulation to compare three approaches, which differed in terms of the time period and selection of trial participants included in the analysis.